#include <iostream>

using namespace std;

class Box
{
    double length;
    double breadth;
    double height;

public:
    double getVolume(void)
    {
        return length * breadth * height;
    }
    void setLength(double len)
    {
        length = len;
    }
    void setBreadth(double bre)
    {
        breadth = bre;
    }
    void setHeight(double hei)
    {
        height = hei;
    }
    Box operator+(const Box& b)
    {
        Box box;
        box.length = this->length + b.length;
        box.breadth = this->breadth + b.breadth;
        box.height = this->height + b.height;
        return box;
    }
};

int main(void)
{
   Box Box1;                // 声明 Box1，类型为 Box
   Box Box2;                // 声明 Box2，类型为 Box
   Box Box3;                // 声明 Box3，类型为 Box
   double volume = 0.0;     // 把体积存储在该变量中
 
   // Box1 详述
   Box1.setLength(6.0); 
   Box1.setBreadth(7.0); 
   Box1.setHeight(5.0);
 
   // Box2 详述
   Box2.setLength(12.0); 
   Box2.setBreadth(13.0); 
   Box2.setHeight(10.0);
 
   // Box1 的体积
   volume = Box1.getVolume();
   cout << "Volume of Box1 : " << volume <<endl;
 
   // Box2 的体积
   volume = Box2.getVolume();
   cout << "Volume of Box2 : " << volume <<endl;
 
   // 把两个对象相加，得到 Box3
   Box3 = Box1 + Box2;

   volume = Box3.getVolume();
   cout << "Volume of Box3: " << volume << endl;
   return 0;
}